Intaglio-ink composition



Patented July 30, 1929.

UNITED STATES PATENT OFFICE.

GEORGE D. KNIGHT, OF REDWOOD CITY, CALIFORNIA, ASSIGNOR OF MACON, GEORGIA.

TO EMORY WINSHIP,

INTAGLIO-INK COMPOSITION.

No Drawing.

The present invention relates to novel ink compositions and processes of manufacturing the same. More particularly the invent-ion relates to the production of novel intaglio inks and ink bases.

It is the practice in the art of printing etchings, engravings, and work of like character, such for example as the production of high grade prints, reproductions of paintings, and the like, and in the printing of picture sections of newspapers; to form the design, picture, or matter to be printed in copper or metallic surfaced plates or rolls by means of a multiplicity of depressions or recesses of varying depths. The smooth surface of the engraved or etched plate or roll results in the white or uncovered portion ofthe printed matter, and the depressions produce the colors or tones; the nature of the color or tone being dependent upon the depth of depression from the surface of the plate or roll at each point. To etlect printing, the depressions are filled with ink in any suitable manner, the excess ink is wiped from the surface of the roll or plate and the inked plate or roll is then brought into engagement with the surface upon which the impression is to be made. In the usual form of printing press for newspaper work, it is the practice to ink the rolls by causing a portion of the circumference thereof to contact with an ink supply as the rolls rotate. Just before the inked sections of the roll engage the surface upon which the imprint is to be made, a wiping member, commonly termed a doctor blade, engages the surface of the roll to wipe the exoess ink therefrom. For high grade prints, the rolls or plates are usually inked by means of suitable inking rollers or devices which are supplied with the ink from suitable fountains or reservoirs.

The usual printing inks are not adapted and cannot be used for intaglio printing. To be suitable for work of this character, inks must be of a wholly different character than the 'usual printing inks. They must readily spread or fiow over the'plate, must wlpe rea dilv fromthe surface of the roll orplate to leave what is known as a good wipe. They must also have sufiicient adhesiveness to be retained in the depressions of the rolls or plates until brought into contact with the paper, and must have sufficient cohesion to pull out freely from the depressions in the plate and transfer readily to the material 1927. Serial No. 180,344;

upor1 wl1icl1 the imprint is to be made. In additlon, the ink must not form a deposit in the plate depressions, and the constituents of the inks can not set up injurious reactions With the metal of the plates or rolls. For successful high speed printing it is also essential that the ink shall dry with suificient rapidity to avoid setting off on the bars of the folder in newspaper presses, orupon contiguous sheets of stacked freshly printed materlal. A satisfactory ink must also have the proper penetrative properties to rapidly draw or set the ink into the paper a reasonable depth and it must have the necessary cohesion to prevent the ink from spreading laterally, or what is commonly termed bleeding.

I have found it possible to provide improved inks having all of the above noted necessary characteristics which are non-misci ble with water but can be thinned by the use of solvents such as petroleum distillate, gasoline, naphtha, and the like, and which are especially adapted for use in the printing of etchings or engravings, either with or without the addition of coloring material thereto.

Accordingly, an object of the present invention is to provide improved intaglio inks which are free flowing, dry rapidly, and are substantially unafiected by moisture when imprinted upon paper.

A further object of my invention is to provide ink compositions which are especially adapted for use in high grade intaglio printing work.

Another object of my invention is to provide inks of great covering power which are of relatively low costand at the same time produce high grade prints.

A still further object of my invention is to provide compositions of the character mentioned that will permit the incorporation of diluents therein without impairing the desired properties of the inks.

' Other objects of my invention will appear from the more detailed description of my in- 100 vention-set forth below, it being understood that various changes may be made therein by those skilled in the art without departing from the scope and spirit of myinvention as defined in the appended claims.

In the preferred form of my invention, the ink is prepared in the form of a liquid having preferably the consistency of a syrup. I have found that inks prepared and marketed in this form are capable of being thinned by 110 the addition of thinning agents generally used for this purpose without affecting the qualities of the ink when used in intaglio 'Standard Oil Company of California, coming over between 251 to392 Fahrenheit, and 310 to 412 Fahrenheitrespectively, are very well suited for use as solvents and coal tar 'distillates coming over between 1409. and 170 C. and commonly known as solvent naphtha or burning naphtha comprising the xylenes and compounds of xylenes and the like are likewise well adapted for-said purpose. These distillates are lighter than kerosene and heavier than gasoline, and when a hydrocarbon solvent lighter than kerosene and heavier than gasoline is hereinafter referred to, it should be understood that I am referring to said distillates.

Preferably I add to the syrupy liquid produced as above indicated a suitable pigment or pigments, and, if desired, varnish, resins,

- gums, or similar substances may be also added to give the'prints the desired finish, as more particularly pointed out hereafter.

In practice my gilsonite syrup may contain approximately from 7 to 50 per cent, but preferably contains about 34 to 38 per cent gilsonite. This syrup may be prepared in the following proportions and manner: To approximately from 500 to 8,000 grams, depending I upon the syrup consistencydesired, preferably about-4,000 grams of gilsonite is added, about 8,000 cc. either of the petroleum distillates known as IO-P thinner or M &P thinner, and the mixture is heated or otherwise treated to form a miscible suspension or a solution of the gilsonite in the distillate. Be cause of the volatile nature of the distillate, the mixture is preferably confined in an enclosed vessel to prevent loss of the constituents which vaporize during the heating and which when present in the completed inks volatilize at relatively low temperature and aid the drying qualities of the inks. In practlce especially satisfactory results are attalned informing my gilsonite syrup by enclosing the mixture of gilsonite and distillate in a receptacle and then heating the receptacle in a manner to cause a pressure of about pounds per square inch to develop therein for a period of about one hour. In this Way a satisfactory solution or suspension is obtained from which the impurities may be separated, and the syrup is then ready for use as an ink or in the mak ng of ink composiby heating the mixture of gilsonite and solvent to a temperature in excess of 100 0., preferably about 210 0. without the use of pressure.

The gilsonite syrups made in the manner above set forth and especially those with the greater percentages of gilsonite are what I term oil inks for the reason that they have the desired characteristics for the lower grades of intaglio inks, are substantially free from and not miscible with water, and must be thinned by the use of solvents such as petroleum distillates, gasoline, naphtha, carbon tetrachloride or the like. In practice approximately 20 to 7 0 gallons of thinner may be added to secure the desiredconsistency of ink depending upon the depth of etching to be printed and the depth of color desired. IVith my preferred forms of oil inks, about 40 gallons of thinner to 100 gallons of ink gives satisfactory results. They are adapted for the printing of etchings and engravings and will give prints or reproductions of reddishbrown color with a. high gloss. By adding more gilsonite to the solutions or suspensions, deeper colors and heavier inks are produced. By the addition of suitable coloring matter or pigments to my gilsonite syrups, the color may be varied and the mixture may be milled safely to I properly incorporate pigments in colloidal or suspended form therein.

'Ot-her grades of oil ink compositions which I have found are particularly adapted for use in intaglio printing are made by incorporatinga tacky, gummy substance such as resins, gums or varnishes, comprising either linseed -oil and a gum or resin, gums or gum lac and alcohol. or gutta percha or rubber and carbon bisulphide and benzene, and the like, in my improved gilsonite syrups to form vehicles for coloring matter. Such ink compositions may be. prepared for example, in the following manner and proportions by subjecting a mixture of about 6,000 to 12,000 cc. preferably 8000 cc. of a hydrocarbon liquid such as IO-P thinner or M & P thinner and about 2,000 to 6,000 grams, preferably 4,000 grams of gilsonite to a heating operation at a temperature from 70 C. to 300 C., preferably 150 C., for a period of from one-half hour to two hours, preferably about one hour, and separating the impurities therefrom. To the gilsonite syrup formed in this way-is 

